Flesh-Eating Bacteria and Lupus

May 14, 2012 — Infection with flesh-eating bacteria, a condition called called necrotizing fasciitis, has struck Aimee Copeland, a 24-year-old Georgia student who reportedly also has lupus.

It’s estimated that 5 million people worldwide, including 1.5 million Americans, have lupus. Are they at risk of the same life-threatening infection?

WebMD asked Chaim Putterman, MD, chief of rheumatology at Montefiore Medical Center and Albert Einstein College of Medicine in the Bronx, N.Y. With colleagues Mohammad Kamran, MD, and Jane Wachs, MD, Putterman recently reported necrotizing fasciitis in eight of the 449 lupus patients treated at their hospital from 1996 through 2007.

Is necrotizing fasciitis really an infection with flesh-eating bacteria?

The bacteria that cause necrotizing fasciitis really do eat flesh. The bacteria eat away at the tissues under the skin and spread rapidly.

There’s no single kind of flesh-eating bacteria. The drug-resistant staph germ called MRSA causes a particularly difficult-to-treat form, but many other bacteria may be the cause. Over half the time, more than one kind of bacteria is involved.

Infection usually comes from a cut, penetrating wound, or burn. But it can also occur in previously healthy people who did not suffer broken skin.

The infection affects the outer skin only later in the infection. That means a serious infection can be well advanced before it looks as bad as it is.

“It is this relatively normal appearance of the skin that often causes delay in diagnosis,” Putterman and colleagues note in their report.

That may be why 1 in 3 patients with necrotizing fasciitis dies of the infection.

“One reason for the bad prognosis of these patients is a delay in diagnosis,” Putterman says. “That comes from a delay in patients seeking care as well as a delay in doctors making a diagnosis.”

Is a person with lupus at increased risk of infection with flesh-eating bacteria?

Yes, for two reasons.

First, lupus itself makes a person more likely to get all kinds of infections, from colds to skin wounds.

That’s ironic, because lupus itself is caused by a hyperactive immune system that turns against a person’s own body. But the disease also involves a defective immune response to bacteria and to viruses.

The second reason is that immunity-suppressing drugs really help people with lupus.

“But patients pay a price: side effects. And the most common side effect is infection,” Putterman says. “Lupus drugs suppress the same immune responses needed to protect you against foreign invaders such as bacteria.”

Are people with lupus at higher risk of necrotizing fasciitis than other people with immune suppression?

That’s not yet clear, because infection with flesh-eating bacteria is so rare. But Putterman’s team was able to find eight cases in lupus patients at a single hospital.

This suggests “that a heightened awareness is warranted, particularly among lupus patients who are immunosuppressed by virtue of their underlying disease, the therapy they require, or both,” Putterman and colleagues write in their report.